1. Field of the Invention
The present invention relates to a TFT, a resistor element, an LC element attenuating a predetermined frequency band, a semiconductor device on which an integrated circuit combining these elements is mounted, and a method of manufacturing the same.
Note that a semiconductor device in this specification means general devices which can function by using semiconductor characteristics, and all of electro-optic devices, semiconductor circuits and electronic devices are the semiconductor devices.
2. Description of the Related Art
A high frequency integrated circuit (also referred to as MMIC) in which an active element such as a transistor and a passive element such as a capacitor, a resistor or an inductor are formed on one semiconductor substrate is known. An active element such as a MESFET, a HEMT, or a HBT, and a lumped parameter element such as a capacitor, an inductor, or a resistor, and a distributed parameter element such as a microstrip line, or a coplanar line are formed together on a semiconductor substrate in an MMIC. Note that a via hole is used for earthing. It is small and lightweight, and has a good high frequency property, as compared with one on which an active element and a passive element are mounted individually. Because a semiconductor process generally has a high cost, however, when a large area is needed for a passive element, the cost is disadvantageous.
Commonly, a high frequency integrated circuit (MMIC) is configured by integrating a transistor using a single crystal silicon wafer or a transistor using a compound semiconductor, and a chip type inductor or capacitor, and further, a filter element such as a SAW element.
Integration and multifunction of mobile communication devices typified by an analog cellular phone and a digital cellular phone, a PHS terminal and the like, are made by the development of MMIC.
In addition, an active element and a passive element are formed individually, and a circuit that they are mounted on the same semi-insulating substrate is referred to as a HMIC or a HIC. Alternatively, it can be merely referred to as a MIC. An alumina and barium titanate substrate is used for a circuit board, a GaAsPHEMT is used for the active element, a plate electrode shaped chip capacitor, an inductor using a bonding wire, a TaN thin film resistor are used for a lumped parameter element, and a microstrip line is used for a distributed parameter element in the HMIC. Note that a through hole is used for earthing.
In addition, Patent Document 1 describes that a thin film lamination having ten layers or less is formed for a thin film integrated circuit in a thin film process in a complex integrated circuit component. Further, Patent Document 2 describes that a high frequency module is formed by compounding a circuit formed with a TFT and a high frequency filter.
Patent Document 1    Japanese Patent Laid-Open No. Hei 7-45787
Patent Document 2    Japanese Patent Laid-Open No. Hei 10-209464